How to understand the ancient tea-horse road as an ancient logistics channel?

The "Ancient Tea and Horse Road" was a famous trade route in ancient times, which mainly facilitated the trade exchanges between Tibet, Yunnan and Sichuan.

The "Tea Horse Road" is a historical concept with a specific meaning, which refers to the Tang and Song dynasties to the Republic of China between the Han, Tibet to exchange tea and horse and the formation of a major transportation channel. Specifically, the ancient tea-horse road is mainly divided into south and north two roads, namely, Yunnan-Tibet Road and Sichuan-Tibet Road. Yunnan-Tibet Road from the tea-producing areas around the Erhai Sea in western Yunnan, through Lijiang, Zhongdian (today's Shangri-La County), Deqin, Mangkang, Chaya to Chandu, and then by Chandu to Wei-Tibet area. The Sichuan-Tibet Highway starts from the tea-producing area around Ya'an in present-day Sichuan, and first enters Kangding, from which the Sichuan-Tibet Highway is divided into two branches: the northern line is from Kangding to the north, through Daofu, Fuhuo, Ganzi, Dege, Jiangda, and arrives at Chandu (i.e., the northern line of the Sichuan-Tibet Highway nowadays), and then leads to Wei-Tibet area from Chandu; the southern line is from Kangding to the south, through Yajiang, Litang, Batang, Mangkang, and Zuogong to Chandu (i.e., the southern line of the Sichuan-Tibet Highway today), and the southern line leads to Wei-Tibet. Sichuan-Tibet Highway's southern line), and then from Chamdo to the Wei-Tibet area.